JP2007127802A - Manufacturing method of toner, electrostatic charge image developing toner, image forming method, process cartridge, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner having high friction electrification properties capable of preventing filming, and excellent in cleanabilities. <P>SOLUTION: The present invention is a method of manufacturing a toner in which a toner composition containing a toner binder comprising a degenerated polyester resin capable of reacting with an active hydrogen is dissolved or dispersed in an organic solvent, the solution or the dispersion is made to react with a cross-linking agent and/or an elongation agent, and an external additive containing silica-based inorganic fine particles with the primary particle mean diameter of 90-200 nm is added to the color particles obtained from the dispersion from which the solvent is removed. The electrostatic charge image developing toner is manufactured using a mixer of which A2/A1 is 0.94-0.97 wherein A1 is the cross-sectional area with the inner wall of the mixer being the outer periphery, and A2 is the area of a circle with the edge of the moving vane being the outer periphery. The mixing is carried out under the condition of 10×10<SP>3</SP>≤S×T≤25×10<SP>3</SP>wherein T is the total mixing time and S is the peripheral speed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toner manufacturing method, an electrostatic charge image developing toner, an image forming method, a process cartridge, and an image forming apparatus, and more particularly, a toner manufacturing method using a binder containing a polyester resin, and an electrostatic charge image developing. The present invention relates to a toner, an image forming method, a process cartridge, and an image forming apparatus.

  In recent years, high-quality images with high reproducibility have been required for electrophotographic images, particularly full-color images. In particular, in a full-color image, there are many halftone portions, and in order to increase the accuracy of reproduction, it is necessary to increase the number of types of colors that can be reproduced with a smaller particle size. Conventionally, as a method for producing a toner, a kneading and pulverizing method in which a colorant and a binder resin are mixed, and if necessary, a charge control agent and a release agent are mixed, and the resulting mixture is melted, kneaded, and then finely pulverized. As necessary, a classification step for obtaining particles in a desired particle size range was provided.

  However, in the production method by the kneading and pulverization method, the particle shape is indefinite, and further, there is a limit on the particle diameter (a limit on the diameter when producing a small-sized particle group having a specific distribution). Therefore, it cannot respond to the demand for further particle size reduction.

  Therefore, in recent years, in order to overcome the problems in the pulverization method, a toner production method using a suspension polymerization method, an emulsion dispersion method, or the like has been proposed and implemented. The toner particles obtained by the kneading and pulverization method, suspension polymerization method, and emulsification dispersion method are mixed so that external additive particles such as a fluidity imparting agent, a charge control agent, and a cleaning aid adhere to the surface of the toner particles and are fixed. A process is provided. The state in which these external additive particles adhere to the surface of the toner particles greatly affects not only the chargeability of the toner particles but also the image quality. For example, if the adhesive force between the external additive particles and the toner particles is too weak, relatively high powder fluidity and chargeability can be obtained, but problems such as external additive particles adhering to the surface of the photoreceptor occur. .

  In order to solve the above problems, there is a method in which an inorganic oxide is externally added to an electrostatic image developing toner under conditions that satisfy a mixing condition consisting of a product of an external mixing time and a linear velocity to obtain a toner having good charging characteristics. A method has been proposed (see, for example, Patent Document 1), and a method in which silica-based inorganic fine particles and titania-based inorganic fine particles are added to toner base particles of 10 μm or less and mixing is repeated (for example, see Patent Document 2). ).

  As a means for adding and mixing inorganic particles of 20 to 80 nm and toner particles, the relationship between the inner wall in the mixer and the clearance between the blade tips, the external share rate obtained from the blade peripheral speed, and the mixing time is defined within the conditions. Has been proposed (see, for example, Patent Document 3).

In addition, after fixing the powdered silica on the surface of the toner particles by mechanical impact means, by adding an amount of silica smaller than that of the silica, good fluidity with less toner deterioration and image density There has been proposed a method for producing a toner capable of obtaining a toner having a toner (see, for example, Patent Document 4).
JP 2003-140392 A JP 2002-229267 A Japanese Patent No. 2921174 Japanese Patent Publication No.8-12478

  However, the above techniques have the following problems.

  In the method of obtaining a toner by externally adding an inorganic oxide under the conditions satisfying the mixing condition, the surface area per gram is increased in a toner having a small particle diameter, so that a large amount of fluidization is required to obtain fluidity. The agent must be used and mixed to adhere firmly. Furthermore, when adding large and small particles to the toner particles, the mixing of the large particles is insufficient under the conventional conditions for adding and mixing the small particles. There is a problem that the filming phenomenon is easily generated from the particles and forms a film on the surface of the photoreceptor.

  The method of mixing inorganic fine particles of 20 to 80 nm is insufficient for firmly attaching fine particles of 90 nm or more to the toner surface.

  In the method using mechanical impact means, in order to immobilize silica on the surface of the toner particles, an apparatus for applying mechanical impact means is required, which requires an increase in the number of processes and introduction of the apparatus. In addition, since excessive energy is applied to the toner particles due to excessive energy application, there is a risk of excessive grinding and increase in fine powder.

  The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a method for producing a toner that prevents filming, has good cleaning properties, and has high tribocharging properties. To do.

In order to solve the above problems, the invention according to claim 1 is to dissolve or disperse a toner composition containing a toner binder composed of a modified polyester resin capable of reacting with an active hydrogen compound in an organic solvent or dispersion medium. The colored particles obtained by dispersing the solution or dispersion in an aqueous medium containing resin fine particles and removing the solvent from the dispersion obtained by reacting with the crosslinking agent and / or the elongation agent, An electrostatic charge image developing toner production method comprising a mixing step of adding and mixing an external additive containing silica-based inorganic fine particles having an average primary particle size of 90 to 200 nm, wherein the mixing step is performed on an inner wall of the mixer. The mixing step is performed using a mixer in which the ratio A2 / A1 is in the range of 0.94 to 0.97, where A1 is the cross-sectional area as the outer periphery and A2 is the circular area with the tip of the rotating blade as the outer periphery. In Product S × T between the total mixing time T and the circumferential velocity S is, 10 × 10 ³ or more, a method for producing a toner for developing electrostatic images which is characterized in that in a range of 25 × 10 ³ or less.

  The invention according to claim 2 is the method according to claim 1, wherein after the first-stage mixing in which the silica-based inorganic fine particles are added, at least one external additive other than the silica-based inorganic fine particles is added. It is characterized in that the second stage of mixing is performed.

  Further, the invention according to claim 3 is the method according to claim 2, wherein a ratio t2 / t1 between the mixing time t1 of the first stage and the mixing time t2 of the second stage is 1.0 or more and 4.0. It is characterized by being in the following range.

  According to a fourth aspect of the present invention, there is provided an electrostatic charge image developing toner obtained by the production method according to any one of the first to third aspects.

  The invention according to claim 5 is an image forming method in which an electrostatic latent image formed on a photoconductor is developed with toner, and the developed toner is transferred and fixed on a recording medium. Is an image forming method using the toner according to claim 4.

  According to a sixth aspect of the present invention, at least one means selected from a charging means, a developing means containing developer, and a cleaning means, and a photosensitive member are integrally supported, and the image forming apparatus main body is supported. A process cartridge which is detachable, wherein the toner forming the developer is the toner according to claim 4.

  According to a seventh aspect of the present invention, there is provided an image forming apparatus having a process cartridge which is detachably attached to the main body of the image forming apparatus, wherein the process cartridge is the process cartridge according to the sixth aspect. The image forming apparatus is characterized by the above.

  According to the present invention, it is possible to produce a toner that prevents filming, has good cleaning properties, and has high tribocharging properties.

  Hereinafter, a toner manufacturing method according to an embodiment of the present invention will be described in detail with reference to the drawings. The embodiments described below are preferred embodiments of the present invention, and therefore technically preferable various kinds of limitations are given. However, the scope of the present invention is not limited to the following description. As long as there is no description which limits, it is not restricted to these aspects.

The method for producing a toner according to an embodiment of the present invention involves mixing an additive containing silica-based inorganic fine particles having a number average particle diameter of 90 nm to 200 nm on the surface of toner particles composed of at least a resin, a colorant, and a release agent. The ratio A1 / A2 between the inner wall cross-sectional area A1 of the mixer and the area A2 of the circle whose outer periphery is the blade tip when the rotating blade rotates is 0.94 to 0.97, and the peripheral speed S and the mixing time T And the product S × T is in the range of 10 × 10 ³ ≦ S × T ≦ 25 × 10 ³ .

  FIG. 1 is a cross-sectional view of a high-speed stirring mixer used in a method for producing a toner for developing an electrostatic image according to an embodiment of the present invention. FIG. 1 shows a high-speed agitation type mixer used in the method for producing a toner for developing an electrostatic charge image according to the present invention, wherein 1 is a mixing tank body 1, 2 is a powder discharge port, 3A and 3B are Rotating blades, 4 is a laminar flow plate, 5 is a lid for mixing in a sealed state, 6 is a jacket for heating or cooling the mixer to a constant temperature, and 7 is a cooling medium. Or it is an inlet of a heating medium, 8 is an exit of a cooling medium or a heating medium.

  In the present invention, the ratio A1 / A2 between the cross-sectional area A1 of the inner wall of the mixer as shown in FIG. 1 and the rotating area A2 of the rotary blades 3A and 3B is set to a range of 0.94 or more and 0.97. By doing so, the gap between the tip of the rotary blade and the inner wall of the mixer can be made as small as possible.

  By using a mixer in the range as described above, the aggregates in the inorganic fine particles can be crushed and uniformly added to the toner. When A1 / A2 exceeds 0.97, the gap between the tip of the rotating blade and the inner wall of the mixer becomes too small, and the tip of the rotating blade may come into contact with the inner wall of the mixer, which is not preferable. If it is less than 0.94, the aggregates present in the inorganic fine particles are present in the toner without being crushed and are not sufficiently adhered to the toner particles. There is a possibility of causing problems such as adhesion to the surface.

Further, by setting the product S × T of the peripheral speed S and the mixing time T to a range of 10 × 10 ^{3 to} 25 × 10 ³ , silica-based inorganic fine particles having a number average particle diameter of 90 nm to 200 nm are strongly adhered to the toner surface. It can be attached. When the product S × T of the peripheral speed S and the mixing time T is less than 10 × 10 ³ , the mixing energy is low. When the product S × T exceeds 25 × 10 ³ , frictional heat generation between the toners increases, and the toner surface starts to melt. The adhering additive is taken in and aggregates are generated. In addition, as the atmosphere at the time of mixing becomes higher, there arises a problem that the release agent dispersed in the toner is dissolved on the toner surface. Therefore, the temperature of the solution or dispersion during mixing is 40 ° C. or less. It is desirable that

In another embodiment, it may be preferable to add the external additive in two stages. In this case, first, after performing a first dispersion step in which only silica-based inorganic fine particles having a number average particle diameter of 90 nm to 200 nm are added to and mixed with the toner particles, inorganic fine particles of other external additives are added to the second stage. Mix.
By mixing only silica-based inorganic fine particles in the first stage, the fluidity is lowered, and the fixation is further promoted by rubbing between the toners. At this time, the ratio (t2 / t1) of the mixing time (t1) of the first stage and the mixing time (t2) of the second stage is in a range where 1.0 ≦ (t2 / t1) ≦ 4.0. Then, it is possible to obtain a toner that is more excellent in filming properties. However, when t1 becomes long, the fixation of the silica-based inorganic fine particles having a large particle size is promoted too much, which may affect the cleaning property, the charging stability, etc., and the first mixing time (t1) is: A range of 60 to 180 seconds is preferable.

  As inorganic fine particles to be added in addition to the silica-based inorganic fine particles, silica-based inorganic fine particles, titania-based fine particles, or both of these may be used. The silica-based inorganic fine particles are preferably hydrophobized, specifically HDK H 2000, HDK H 2000/4, HDK H 2050EP, HVK21 (manufactured by Hoechst), R972, R974, RX200, RY200, R202. , R805, R812 (manufactured by Nippon Aerosil Co., Ltd.) and TS720 (manufactured by Cabot).

  As titania-based fine particles, P-25 (Nippon Aerosil), STT-30, STT-65C-S (above Titanium Industry), TAF-140 (Fuji Titanium Industry), MT-150W, MT-500B, MT-600B ( Taker)). As the hydrophobized titanium oxide fine particles, anatase-type or rutile-type crystalline or non-crystalline ones can be used, and T-805 (Nippon Aerosil) or rutile-type MT-100S, MT -100T, MT150A, MT150AFM (above Taka), STT-30A, STT-62S-S (above Titanium Industry), IT-S (Ishihara Industry), etc.

  In order to obtain hydrophobized silica fine particles and titania fine particles, hydrophilic fine particles can be obtained by treating with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane. It can also be obtained by polysiloxane treatment. The amount of silica fine particles used is set in the range of 0.2 to 1.5% by weight. If the amount of silica fine particles added is less than 0.2%, the effect of imparting fluidity and improving the degree of aggregation cannot be exhibited. If the amount added exceeds 1.5%, the silica particles adhere to the photosensitive drum in the copying machine, and the medaka Cause abnormal images. The amount of titania fine particles used is set in the range of 0.1 to 2.0% by weight. If the amount of titania fine particles added is less than 0.1%, the coverage of the titania fine particles with respect to the toner surface becomes small, and improvement in storage stability cannot be achieved. On the other hand, if it exceeds 2.0%, an abnormal image is generated as in the case of the silica.

  The mixer for mixing the colored particles and the external additive is not particularly limited as long as it has a rotating blade and can cool or heat the entire container. Examples of the mixer that satisfies these points include a Henschel mixer (made by Mitsui Mining) and a super mixer (made by Kawata).

  Next, the toner base before the processing of the external additive will be described. The components of the toner base before the external additive treatment used in the production method of the present invention comprises a resin, a colorant, a charge control agent, and a release agent.

  Examples of the resin include a modified polyester resin capable of reacting with an extender and / or a crosslinking agent, for example, a polyester prepolymer (A) having an isocyanate group. Examples of the prepolymer (A) include a polycondensate of a polyol (1) and a polycarboxylic acid (2) and a polyisocyanate (3) reacted with a polyester having active hydrogen. Examples of the group having active hydrogen in the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferable.

  As the crosslinking agent and / or extender, amines (B) can be preferably used. The toner according to the exemplary embodiment of the present invention preferably contains, as a toner binder, a urea-modified polyester (i) that can be obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). In the toner according to the exemplary embodiment, the glass transition point (Tg) of the toner binder is 40 to 70 ° C., preferably 55 to 65 ° C. When the glass transition point is less than 40 ° C., the heat-resistant storage stability of the toner deteriorates, and when the glass transition point exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of the urea-modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with known polyester-based toners.

  As the colorant of the toner according to the exemplary embodiment of the present invention, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium Yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG) , Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Parared, Faiselle , Parachlor ortho nitroaniline red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX , Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y , Alizarin lake, thioindigo red B, thioindigo maroon, oil red, quinacridone , Pyrazolone red, polyazo red, chrome vermilion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal free phthalocyanine blue, phthalocyanine blue, fast sky blue , Indanthrene Blue (RS, BC), Indigo, Ultramarine, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian , Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Maracay Togreen lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithopone and mixtures thereof can be used. The content of the colorant is usually 1 to 15 wt%, preferably 3 to 10 wt%, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As the binder resin to be kneaded together with the production of the masterbatch or the masterbatch, in addition to the modified and unmodified polyester resins mentioned above, styrene such as polystyrene, poly p-chlorostyrene, and polyvinyltoluene, and polymers of substituted products thereof; Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α- Chloromethyl methacrylate copolymer, Len-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic Styrene copolymers such as acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, urethane, urea modified polyester, epoxy resin, epoxy polyol resin, polyurethane, Polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. These can be used alone or in combination.

  The master batch can be obtained by mixing and kneading the resin for the master batch and the colorant under high shearing force and kneading. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin. Also, a so-called flushing method called watering paste containing water of a colorant is mixed and kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shearing dispersion device such as a three-roll mill is preferably used.

  As the release agent of the present invention, known ones can be used, for example, polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sazol wax, etc.); carbonyl group-containing wax, etc. It is done. Of these, carbonyl group-containing waxes are preferred. Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecandiol diol distearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylene diamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred. The melting point of the wax of the present invention is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability. The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

  In view of removal later, the organic solvent is preferably volatile with a boiling point of less than 150 ° C. from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more.

  A urea-modified polyester (UMPE) can be obtained by reacting the polyester prepolymer (A) having an isocyanate group with the amine (B). As a method for stably forming a dispersion composed of a modified polyester such as urea-modified polyester or a prepolymer (A) in an aqueous medium, the dispersion is made of a modified polyester or prepolymer (A) such as a urea-modified polyester in an aqueous medium. Examples thereof include a method in which the composition of the toner raw material is added and dispersed by shearing force. The prepolymer (A) and other toner composition (hereinafter referred to as toner raw material), a colorant masterbatch, a release agent, an unmodified polyester resin, etc. are dissolved or dispersed in an organic solvent in advance. Then, the solution or dispersion is added and dispersed in an aqueous medium.

  As an aqueous medium used in the embodiment of the present invention, water alone may be used, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like.

  A method for dispersing in an aqueous medium is not particularly limited, and known equipment such as a low-speed shearing type, a high-speed shearing type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. A high-speed shearing method is preferable in order to make the particle diameter of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1,000 to 30,000 rpm, preferably 5,000 to 20,000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferred in that the dispersion of the urea-modified polyester or prepolymer (A) has a low viscosity and is easy to disperse.

  The amount of the aqueous medium used is usually 50 to 2,000 parts by weight, preferably 100 to 1,000 parts by weight, based on 100 parts of the toner composition containing a polyester such as urea-modified polyester or prepolymer (A). If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 2,000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

  The elongation and / or cross-linking reaction time is selected, for example, depending on the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. It's time. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

  In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. Alternatively, the emulsified dispersion can be sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant can be removed by evaporation together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln.

  The smaller the volume average particle diameter Dv of the toner, the better the fine line reproducibility can be improved. However, since the cleaning property decreases as the particle size decreases, it is preferably at least 3 μm. In particular, if 20% or more of toner of 2 μm or less is present, the amount of toner having a small particle size that is difficult to be developed on the surface of the magnetic carrier or the developing roller increases. Insufficient reverse chargeable toner increases, background stains occur, and image quality deteriorates.

  Moreover, it is preferable that the particle size distribution represented by ratio (Dv / Dn) of the volume average particle diameter Dv and the number average particle diameter Dn is 1.05-1.20. By sharpening the particle size distribution, the toner charge amount distribution becomes uniform and background fogging can be reduced. When Dv / Dn exceeds 1.20, the charge amount distribution of the toner becomes wide, and it becomes difficult to obtain a high-quality image. The particle size of the toner up to this point is 50, using a Coulter Counter Multisizer (manufactured by Coulter), selecting and using an aperture with a measurement hole size of 100 μm corresponding to the particle size of the toner to be measured. This was done by measuring the average particle size of 000 particles.

  The toner according to the exemplary embodiment of the present invention may contain a charge control agent as necessary. All known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified). Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of phenol-based condensate (above, manufactured by Orient Chemical Industries), TP-302, TP-415 of quaternary ammonium salt molybdenum complex (above, manufactured by Hodogaya Chemical Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit), copper phthalocyanine, perylene, quinaclide And azo pigments, and other high molecular compounds having a functional group such as a sulfonic acid group, a carboxyl group, and a quaternary ammonium salt.

  In the present invention, the amount of charge control agent used is determined by the toner production method including the type of binder resin, the presence or absence of additives used as necessary, and the dispersion method, and is uniquely limited. However, it is preferably used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline.

  The toner according to the embodiment of the present invention can be used as a two-component developer. In this case, it may be used by mixing with a magnetic carrier, and the content ratio of the carrier to the toner in the developer is preferably 1 to 10 parts by weight of the toner relative to 100 parts by weight of the carrier. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride and non- Monomers including a fluoro terpolymers such, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited only to these examples. In the following examples, parts and% are based on weight unless otherwise specified.

[Example 1]
1. Synthesis of unmodified polyester In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 690 parts of bisphenol A ethylene oxide 2-mol adduct and 256 parts of terephthalic acid were placed, and at 230 ° C. for 8 hours at normal pressure. Next, the reaction was carried out at a reduced pressure of 10 to 15 mmHg for 5 hours, followed by cooling to 160 ° C., 18 parts of phthalic anhydride was added thereto and reacted for 2 hours to obtain unmodified [Polyester (B)].
2. Synthesis of prepolymer In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2 mol adduct, 81 parts of bisphenol A propylene oxide 2 mol adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 parts of acid and 2 parts of dibutyltin oxide were added, reacted at 230 ° C. for 8 hours at normal pressure, further reacted for 5 hours at a reduced pressure of 10-15 mmHg, then cooled to 160 ° C., and 32 parts of phthalic anhydride was added thereto And reacted for 2 hours. Next, the mixture was cooled to 80 ° C. and reacted with 230 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate group-containing [prepolymer (A)].
3. Synthesis of ketimine In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound (1)].

1. Production of base toner Into a tank, 14.3 parts of the above [prepolymer (A)], 55 parts of [polyester (B)] and 78.6 parts of ethyl acetate were stirred and dissolved. Next, 10 parts of rice wax (melting point 83 ° C.) as a release agent and 4 parts of copper phthalocyanine blue pigment were added, stirred at 12,000 rpm for 15 minutes with a TK homomixer at 60 ° C., and at 20 ° C. for 60 minutes with a bead mill. Distributed. This is designated as [toner material solution (1)]. Next, 306 parts of ion-exchanged water, 265 parts of a 10% tricalcium phosphate suspension, and 0.2 part of sodium dodecylbenzenesulfonate were placed in a tank and dissolved uniformly. Then, while stirring at 12,000 rpm with a TK homomixer, 2.7 parts of the above [toner material solution (1) and ketimine compound (1) were added to cause a urea reaction. When the particle size was large while observing the particle size and particle size distribution with an optical microscope, the stirring rotation speed was increased to 14,000 rpm and the operation was further performed for 5 minutes. The solvent removal process was performed by the following method. The emulsified dispersion obtained in the previous step was transferred to a tank equipped with a stirring blade and a thermometer, heated to 45 ° C., and the solvent was removed under atmospheric pressure (101.3 kPa). Then, after filtering off, washing and drying, colored particles were obtained.

  With respect to 100 parts of the colored particles obtained above, 0.3 part of hydrophobic silica having a number average particle diameter of 110 nm, 0.7 part of hydrophobic silica having a number average particle diameter of 30 nm, and titanium oxide having a number average particle diameter of 50 nm .5 parts were weighed and added to a Henschel mixer for mixing. The mixing conditions at this time are shown in Table 1 below.

[Examples 2 to 4, Comparative Examples 1 to 3]
The colored particles obtained by the same method as in Example 1 were mixed by the same external additive formulation as in Example 1 except that the mixing conditions were changed. The mixing conditions at this time are shown in Table 1.
Table 1 shows the charge amount and the external additive aggregate amount of the toners obtained in the above Examples and Comparative Examples. The amount of the external additive aggregate was determined as follows.

  1 g of toner was weighed, charged into a metal cylinder with a mesh and blown, and then the particles on the mesh were observed with a microscope (VHX-100 manufactured by Keyence) with a 150 × lens, and the number of aggregates on the mesh was measured. . Note that the number is the number of visual measurements within 16 mm 2.

A developer composed of 5% by weight of toner subjected to external additive treatment and 95% by weight of a copper-zinc ferrite carrier coated with a silicone resin and having an average particle diameter of 40 μm can be prepared, and 45 sheets of A4 size paper can be printed per minute. Evaluation was made using the Ricoh imagio Neo 450 according to the following criteria, and the results are shown in Table 1.
(A) Background stain The blank image is stopped during development, the developer on the developed photoreceptor is tape transferred, and the difference from the image density of the untransferred tape is measured by 938 Spectrodensitometer (manufactured by X-Rite) ) “◯” indicates that there is no problem in practical use, “Δ” indicates that there is no problem in practical use although it is somewhat inferior, and “X” indicates that there is a problem in practical use.
(B) Cleaning After copying 100K sheets continuously, the transfer residual toner on the photoconductor passed through the cleaning process is transferred to a white paper with Scotch tape (manufactured by Sumitomo 3M Co., Ltd.), and measured with a Macbeth reflection densitometer RD514. A case where the difference from the blank was 0.01 or less was evaluated as ○ (good), and a case where the difference was more than that was evaluated as × (defective).
(C) Filming was continuously performed on 100K sheets (printing rate: 6%), and after 100K sheets, it was confirmed whether filming had occurred on the photoreceptor. The filming on the photoreceptor was evaluated by visually classifying the grade into five levels, with the better grade being ranked 5 and the worse grade being ranked 1.

  From Example 1 and Comparative Examples 1 to 3, it was confirmed that the toner obtained under the mixing condition according to the embodiment of the present invention has good results in charging property, filming property, and cleaning property. Examples 2 and 3 are methods in which only 110 nm silica-based inorganic fine particles are added and mixed in the first stage, and then two other types of external additives are mixed. Compared with Example 1, It was confirmed that a filming property equal to or higher than that was obtained. In Example 4, the total mixing time is the same as that in Example 2, but since the time t1 is extended, the cleaning after 100K is deteriorated.

  As mentioned above, the invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the above, and various modifications can be made without departing from the scope of the invention. Needless to say.

It is sectional drawing of the high-speed stirring type mixer used for the toner manufacturing method for electrostatic image development concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mixing tank main body 2 Powder discharge port 3A, 3B Rotary blade 4 Laminar flow plate 5 Lid 6 Temperature control jacket 7 Temperature control water inlet 8 Temperature control water discharge

Claims (7)

Dissolve or disperse a toner composition containing a toner binder made of a modified polyester resin capable of reacting with an active hydrogen compound in an organic solvent or dispersion medium, and disperse the solution or dispersion in an aqueous medium containing resin fine particles. And an external additive containing silica-based inorganic fine particles having an average primary particle size of 90 to 200 nm at least to colored particles obtained by removing the solvent from the dispersion obtained by reacting with a crosslinking agent and / or an extender. A method for producing a toner for developing an electrostatic image having a mixing step of adding and mixing an agent,
In the mixing step, the ratio A2 / A1 is in the range of 0.94 to 0.97, where A1 is a cross-sectional area with the inner wall of the mixer as the outer periphery and A2 is the circular area with the tip of the rotating blade as the outer periphery. Electrostatic charge image development using a mixer, wherein the product S × T of the total mixing time T and peripheral speed S in the mixing step is in the range of 10 × 10 ³ or more and 25 × 10 ³ or less. Of manufacturing toner.   The first-stage mixing for adding the silica-based inorganic fine particles is followed by the second-stage mixing for adding at least one external additive other than the silica-based inorganic fine particles. A method for producing the toner for developing an electrostatic image according to claim 1.   3. The electrostatic charge image development according to claim 2, wherein a ratio t2 / t1 of the mixing time t1 of the first stage and the mixing time t2 of the second stage is in a range of 1.0 or more and 4.0 or less. Of manufacturing toner.   An electrostatic charge image developing toner obtained by the production method according to claim 1. An image forming method in which an electrostatic latent image formed on a photoreceptor is developed with toner, and the developed toner is transferred and fixed on a recording medium,
An image forming method using the toner according to claim 4 as the toner. A process cartridge that integrally supports at least one means selected from a charging means, a developing means containing developer, and a cleaning means, and a photosensitive member, and is detachable from the image forming apparatus main body;
The process cartridge according to claim 4, wherein the toner forming the developer is the toner according to claim 4. An image forming apparatus equipped with a process cartridge which is detachable from the image forming apparatus main body,
The image forming apparatus according to claim 6, wherein the process cartridge is a process cartridge according to claim 6.

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